Tightly sealed cartons



1953 R. J. HENNESSEY ETAL 3,112,855

I TIGHTLY SEALED CARTONS Filed Nov. 6, 1961 2 Sheets-Sheet l INVENTOR frusssu J. HEN/V5835) Fry/v04 as Gurff? 5 JOHN /7. MYERS ELM nn ATTORNEY 3, 1963 R. J. HENNESSEY ETAL 3,112,355

TIGHTLY SEALED CARTONS Filed Nov. 6, 1961 2 Sheets-Sheet 2 INVENTOR Russia HEW/visas? Fir/v04 0s .,\GUYR JOHN H. MYERS ATTORNEY United States Patent 3,112,855 TIGHTLY SEALED CARTONS Russell J. Hennessey, St. Paul, Reynolds Guyer, White Bear, and John H. Myers, St. Paul, Minn., assignors to Waldorf Paper Products Company, a corporation of Minnesota Filed Nov. 6, 1961, Ser. No. 150,348 1 Claim. (Cl. 229-43) This invention relates to an improvement in tightly sealed cartons and deals particularly with a carton having tightly sealed ends.

For many years attempts have been made to produce cartons which are moisture vapor proof, liquid proof and the like. Many such cartons have been produced, but they are usually diflicult to form, and diflicult to seal at high speed. It is an object of the present invention to provide a carton which eliminates the major source of leakage in an ordinary paste end carton. Many tests have shown that regular paste end cartons normally leak to the greatest extent at the end closures due to improper seal. An object of the present invention lies in the provision of an inner end closure which will increase the effectiveness of the closure.

An added feature of the present invention resides in the provision of an end closure which may be used to accommodate an item segregated from the remainder of the product. As an example, for many years a confection has been sold containing a prize. The Pure Food Laws now usually prevent such a prize being placed directly in the carton with the confection, making it necessary to enclose the prize or to place it in an envelope. It is a feature of the present invention that the inner closure forms a partition defining a shallow receptable into which such an object may be placed.

A feature of the present invention resides in forming a tray-shaped body of thin flexible plastic sheeting, to place the tray in the end of the cart-on, and to heat seal the walls of the tray to the walls of the carton to thereby provide an airtight barrier. The tray is usually provided with projecting flanges which may be sealed to the inner surfaces of the closing flaps. As a result, the carton may thereafter be sealed on regular cart-on closing equipment, the closing flaps merely serving to hold the inner closure in proper position and to protect it. If desired, an article or insert may be placed in the tray prior to the closing of the flaps.

These and other objects and novel features of the present invention will be more clearly and fully set forth in the following specification and claim.

In the drawings forming a part of the specification:

FIGURE 1 is a perspective view of an inner closure member which is designed for insertion into the carton.

FIGURE 2 is a perspective view of an end of the carton showing the inner closure in place therein.

FIGURE 3 is a perspective view of the carton after two of the flaps have been folded into closed position.

FIGURE 4 is a perspective view of the carton after an additional flap has been folded into closed position.

FIGURE 5 is a perspective view of the fully closed carton.

FIGURE 6 is a cross sectional view through the closed carton end.

FIGURE 7 is a perspective view of a modified form of inner closure.

FIGURE 8 is a perspective view of a carton showing the inner closure of FIGURE 7 in place therein.

FIGURE 9 is a perspective view of the carton in partially closed position.

FIGURE 10 is a perspective view of the cart-on end after a sub-sequent folding operation.

3,112,855 Patented Dec. 3, 1963 "ice FIGURE 111 is a perspective view of a completely closed carton.

FIGURE 12 is a sectional view through the carton closure in closed position.

The carton A is a conventional tubular paste end carton including parallel side walls 10 and parallel end walls 11 connected in tubular relation. The side walls 10 are provided with opposed closing flaps 112 which are usually approximately equal in area to the cross section of the carton. The end walls 11 are provided with closure flaps 13 which are of an area less than one-half the cross sectional area of the carton, so that the flaps 13 may fold down in a common plane.

The inner closure B is formed of a film of thin flexible plastic sheeting such as that commercially known as Saran. The sheet is molded or vacuum formed to provide a central generally rectangular pocket 14 of proper dimensions to snugly fit within the end of the carton between the side walls 10 and end walls 11. The pocket 14 includes a bottom closure panel 15, upwardly extending side wall portions 16, and upwardly projecting end walls 17 which are in generally parallel relation. The periphery of the tray shaped pocket includes side flanges 19 and end flanges 20, the flanges 19 and 20 forming a rectangular frame encircling the pocket.

In preferred form, the inner closure B is inserted into the end of the carton A while the closing flaps 12 and 13 are folded outwardly as indicated in FIGURE 2 of the drawings. Preferably, the carton A is positioned in a rectangular pocket during the closing operation, and an expandable mandrel extends into the pocket and seals the walls of the pocket 14 against the inner surfaces of the carton walls. The inner surfaces of the carton walls are provided with a heat scalable film thereupon which is either coated on the paper board or laminated thereto. During the heat sealing operation, the peripheral flanges 19 and 20 may also be sealed to the closing flaps 12 and 13 if it is so desired.

To complete the operation, the end wall flaps 13 are folded inwardly into the position illustrated in FIGURE 3 of the drawings, this action also folding the end wall flanges 20 inwardly as shown in this figure. The side wall flaps 12 and 13 are then sequentially folded down as indicated in FIGURES 4 and 5 of the drawings, and the flaps are secured together in any suitable manner. The flaps may be closed by heat sealing, but usually adhesive is applied to selected surfaces to hold the carton closed in the manner illustrated in FIGURES 5 and 6 of the drawings.

If the inner closure B is to be used for containing an insert or object segregated from the remainder of the carton contents, the article such as C may be inserted in the pocket 14 after the inner closure has been secured to the carton. The inner closure thus forms a separate receptacle which maintains the article C out of contact with the remainder of the carton contents.

The structure shown in FIGURES 7- 12 of the drawings is somewhat similar to the inner closure B, but does not seal continuously to the entire inner wall surface. The inner closure D comprises a flat sheet of heat sealable material which is molded to form two generally wedge shaped pockets 22 each defined by an inclined bottom wall 23, triangular side wall portions 24, and a rectangular end wall portion 25. When the closure D is inserted into the end of the carton, the end Walls 25 and side Walls 24 fit snugly Within the end walls 11 and side walls 10 of the carton A. Force is applied to seal these walls against the portions of the carton walls which they engage. The marginal side edge portions 26 and end edge portions 27 of the closure D are sealed in face contact with the closing flaps l2 and 13 while these closing flaps are folded outwardly into a common plane.

The carton is closed in the same manner as was previously described, the end flaps 13 being folded inwardly to a common plane, folding the marginal edge portions 27 of the inner closure D at the same time. The side Wall fiaps 12 are then folded inwardly and downwardly one after the other as is indicated by FIGURES 10 and ,11 of the drawings. The closing flaps 12 and 13 are secured in closed positions by any suitable means such as heat sealing or by adhesive.

In accordance with the patent statutes, we have described the principles of construction and operation of our improvement in tightly sealed cartons, and while we have endeavored to set forth the best embodiment thereof, we desire to have it understood that changes may be made within the scope of the following claim without departing from the spirit of our invention.

We claim:

A carton closure in combination with a rectangular tubular carton having parallel side walls and parallel end walls, closure flaps hinged to the ends of said side and end walls and foldable into superposed relation, the walls and flaps including a heat scalable inner surface, an inner closure comprising a thin flat rectangular sheet of material capable of being heat sealed to said surface, a pair of spaced preformed pocket means in said sheet spaced from the edges thereof, said pockets being wedge shaped in section having downwardly and outwardly inclined bottom panels, triangular side walls, and parallel end walls, the side and end walls of said pockets being in face contact with the side and end walls of the carton and sealed thereto and the marginal edges of said sheet being sealed in face contact to said closure flaps.

References Cited in the file of this patent UNITED STATES PATENTS 1,693,841 Gaylord Dec. 4, 1928 2,452,952 Palmer Nov. 2, 1948 2,496,043 Farrell Jan. 31, 1950 2,857,881 Beebe et al. Oct. 28, 1958 

